25287816421 has 16 divisors (see below), whose sum is σ = 30969074304. Its totient is φ = 20154461184.

The previous prime is 25287816413. The next prime is 25287816439. The reversal of 25287816421 is 12461878252.

It is a cyclic number.

It is not a de Polignac number, because 25287816421 - 2³ = 25287816413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25287814421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1270260 + ... + 1290013.

It is an arithmetic number, because the mean of its divisors is an integer number (1935567144).

Almost surely, 2^25287816421 is an apocalyptic number.

It is an amenable number.

25287816421 is a deficient number, since it is larger than the sum of its proper divisors (5681257883).

25287816421 is a wasteful number, since it uses less digits than its factorization.

25287816421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2560380.

The product of its digits is 430080, while the sum is 46.

The spelling of 25287816421 in words is "twenty-five billion, two hundred eighty-seven million, eight hundred sixteen thousand, four hundred twenty-one".